Improvement



UNITED STATES PATENT OFFICE. f

JOHN W. DIXON, OF PHILADELPHIA,` PENNSYLYANIA.

IMPROVEMENUN APPARATUS `Foa MAKINGPAPERPULP.

Specification forming part of Letters Patent No. 52,5%4, dated February 13, 1866.

To all whom 'it may concern.'

Be it known that I, JoHN W. DrXoN, of the city of Philadelphia and State ot' Pennsylvania, have invented anew and useful Improvement in Apparatus for Making Paper-Pulp; amLI do hereby declare the following to be a full and exact description of the same, reference being -had to the annexed drawing, making a part of this specification, which represents, a vertical section of my imi-moved apparatus.

Myimprovement has ior its object the digesting Wood, straw, and other vegetable fibrous material for making paper-pulp, and may be 'also used for, boiling rags or bleaching or preparing dax or similar matters. 4 4

A is a strong close boiler capable of resisting considerable pressure, and intended for a digester. Itis provided with a man-hole, B, at the top, -and also with a side tube or arm, o.

D is a perforated diaphragm. placed near the bottom. y

E is a tube passing off laterally above the l perforated diaphragm, having either a plug- .cock, F, inside, worked by a rod and screw,H,

passing through a stuffing-box opposite, or a slidevalve, K, or other convenient valve arrangement. v

L is a draw-od' cock. A series ot' circulating-.tubes,fM M M `M, extend from below the diaphragm D to the upper part of the digester. The heat isto be applied to the bottom of the digester from a plication for a patent, and a steam-heating coil may be placedl below D, if desired.

digesting-liquor while the'digestin g operation is progressing, it can be effected by having an auxiliary injection-pump or injector placed on thedigester A and operated to4 force in fresh water. or digesting-liquid, while the drawoif cock is open'ed to'permit a corresponding escape ot'refuse liquid in the manner describedby me in a'former patent. i.' e.

being closed, the material and digesting-liquor, either water or alkaline or other solution, are to be fed inthrough the arm G, which is then closed by a tight-titting' cover. After `the' -material hasbeen pulped or digested it is drawn oft' through -the tube E'. The tube C may be extended above the level of the top ofthe .boiler A to insure'the boiler being kept full or nearly t'ull of liquor. no upper perforated diaphragm is required, although it may be used, in which caseitshoul'd be placed above the point' at which the arm C branches from the main boiler.

Having thus described my improvement, what I claim as my invention, and desire to secure by Letters Patent, is-

l.' rlhe combination ot the digester A, the perforated diaphragm l), and .tlYe lateral pulp-l passage E, arranged. a'.1'l,.o1. erating, as described.

2. The combination of the digester A and circulating-tubes M M MUM/f', extending from the lower to 'the upper part of the digester, for causin ga circulation ofthe d'igestingliquor by the eii'ect ofthe heat on these tubes. I

l 3. The combination ot the digester A, the tube C, and the lateral pulppassage E, 'arranged and operating as described. p

y JOHN W. DIXON.

vWitnesses 4 J. E. SHAW' GEO. BUoKLEY.

d [f it' be desired to renew fresh Water or'fresh `The operation is as follows: The man-hole With this arrangement 

